This invention relates in general to devices for crimping fittings onto the ends of hoses and in particular to a self-contained, portable collet crimping apparatus.
The collet crimping machine is a well known device which is adapted to secure a cylindrical end portion of a metallic fitting onto an end of a high pressure hydraulic hose. Initially, the end portion of the fitting is formed having an inner diameter which is slightly larger than the outer diameter of the hose, permitting the end of the hose to be loosely inserted therein. Then, the end of the hose and the fitting are inserted within the collet crimping machine. When the collet crimping machine is actuated, the fitting is crimped so as to permanently deform the tubular end portion thereof about the end of the hose.
To accomplish this, a typical collet crimping machine is provided with a hydraulic actuator which is adapted to engage a contractable die assembly. The hydraulic actuator includes a cylinder having a piston slidably disposed therein. When pressurized hydraulic fluid is supplied to the interior of the cylinder, the piston is moved from a first position to a second position. The die assembly typically includes a die ring having a tapered inner surface and a plurality of collet segments disposed within the die ring. A spacer or pusher is disposed between the piston of the hydraulic actuator and the collet segments. Thus, when the piston is moved to the second position, the pusher is moved to engage and move the collet segments. Because of their engagement with the tapered inner surface of the die ring, the collet segments are contracted inwardly toward one another, thereby crimping the fitting disposed therein about the hose.
Typically, the die assembly is removable from the collet crimping machine. This is done to permit the installation and removal of collet segments of different sizes, which permit the collet crimping machine to crimp fittings of various sizes onto hoses of various sizes. To facilitate the installation and removal of the collet segments, it is known to provide a pusher which is removable from the collet crimping machine. Such removable pushers provide convenient access to the die assembly when changing the collet segments. However, when these pusher are re-installed in the collet crimping machine, they must be carefully aligned between the piston and the die assembly in order to function properly. This careful re-alignment has been found to be undesirably time consuming after each change of the collet segments. Also, although removable pushers are typically retained to the collet crimping machine in some manner, such as by a chain, they have occasionally become separated therefrom and lost. Accordingly, it would be desirable to provide a collet crimping machine wherein the pusher is secured thereto, yet which is movable between extended and retracted positions to facilitate changing of the collet segments.
As mentioned above, the collet crimping machine typically includes a hydraulic actuator which is operated by the application of pressurized hydraulic fluid thereto. In a manufacturing situation, the collet crimping machine can be connected to any conventional external source of pressurized fluid which is commonly available in the manufacturing environment. However, often it is necessary to repair fittings and hoses in the field, where a source of pressurized fluid is not readily available. Accordingly, it would also be desirable to provide a collet crimping machine having a self-contained source of pressurized hydraulic fluid, thereby facilitating the use thereof in the field.